xref: /csrg-svn/sys/vax/if/if_ec.c (revision 14269)
1 /*	if_ec.c	6.1	83/07/29	*/
2 
3 #include "ec.h"
4 
5 /*
6  * 3Com Ethernet Controller interface
7  */
8 #include "../machine/pte.h"
9 
10 #include "../h/param.h"
11 #include "../h/systm.h"
12 #include "../h/mbuf.h"
13 #include "../h/buf.h"
14 #include "../h/protosw.h"
15 #include "../h/socket.h"
16 #include "../h/vmmac.h"
17 #include "../h/ioctl.h"
18 #include "../h/errno.h"
19 
20 #include "../net/if.h"
21 #include "../net/netisr.h"
22 #include "../net/route.h"
23 #include "../netinet/in.h"
24 #include "../netinet/in_systm.h"
25 #include "../netinet/ip.h"
26 #include "../netinet/ip_var.h"
27 #include "../netinet/if_ether.h"
28 #include "../netpup/pup.h"
29 
30 #include "../vax/cpu.h"
31 #include "../vax/mtpr.h"
32 #include "../vaxif/if_ecreg.h"
33 #include "../vaxif/if_uba.h"
34 #include "../vaxuba/ubareg.h"
35 #include "../vaxuba/ubavar.h"
36 
37 #define	ECMEM	0000000
38 
39 int	ecprobe(), ecattach(), ecrint(), ecxint(), eccollide();
40 struct	uba_device *ecinfo[NEC];
41 u_short ecstd[] = { 0 };
42 struct	uba_driver ecdriver =
43 	{ ecprobe, 0, ecattach, 0, ecstd, "ec", ecinfo };
44 #define	ECUNIT(x)	minor(x)
45 
46 int	ecinit(),ecioctl(),ecoutput(),ecreset();
47 struct	mbuf *ecget();
48 
49 extern struct ifnet loif;
50 
51 /*
52  * Ethernet software status per interface.
53  *
54  * Each interface is referenced by a network interface structure,
55  * es_if, which the routing code uses to locate the interface.
56  * This structure contains the output queue for the interface, its address, ...
57  * We also have, for each interface, a UBA interface structure, which
58  * contains information about the UNIBUS resources held by the interface:
59  * map registers, buffered data paths, etc.  Information is cached in this
60  * structure for use by the if_uba.c routines in running the interface
61  * efficiently.
62  */
63 struct	ec_softc {
64 	struct	arpcom es_ac;		/* common Ethernet structures */
65 #define	es_if	es_ac.ac_if		/* network-visible interface */
66 #define	es_addr	es_ac.ac_enaddr		/* hardware Ethernet address */
67 	struct	ifuba es_ifuba;		/* UNIBUS resources */
68 	short	es_mask;		/* mask for current output delay */
69 	short	es_oactive;		/* is output active? */
70 	u_char	*es_buf[16];		/* virtual addresses of buffers */
71 } ec_softc[NEC];
72 
73 /*
74  * Do output DMA to determine interface presence and
75  * interrupt vector.  DMA is too short to disturb other hosts.
76  */
77 ecprobe(reg)
78 	caddr_t reg;
79 {
80 	register int br, cvec;		/* r11, r10 value-result */
81 	register struct ecdevice *addr = (struct ecdevice *)reg;
82 	register caddr_t ecbuf = (caddr_t) &umem[numuba][ECMEM];
83 
84 #ifdef lint
85 	br = 0; cvec = br; br = cvec;
86 	ecrint(0); ecxint(0); eccollide(0);
87 #endif
88 	/*
89 	 * Make sure memory is turned on
90 	 */
91 	addr->ec_rcr = EC_AROM;
92 	/*
93 	 * Disable map registers for ec unibus space,
94 	 * but don't allocate yet.
95 	 */
96 	(void) ubamem(numuba, ECMEM, 32*2, 0);
97 	/*
98 	 * Check for existence of buffers on Unibus.
99 	 */
100 	if (badaddr((caddr_t)ecbuf, 2)) {
101 	bad1:
102 		printf("ec: buffer mem not found\n");
103 	bad2:
104 		(void) ubamem(numuba, 0, 0, 0);	/* reenable map (780 only) */
105 		addr->ec_rcr = EC_MDISAB;	/* disable memory */
106 		return (0);
107 	}
108 #if VAX780
109 	if (cpu == VAX_780 && uba_hd[numuba].uh_uba->uba_sr) {
110 		uba_hd[numuba].uh_uba->uba_sr = uba_hd[numuba].uh_uba->uba_sr;
111 		goto bad1;
112 	}
113 #endif
114 
115 	/*
116 	 * Tell the system that the board has memory here, so it won't
117 	 * attempt to allocate the addresses later.
118 	 */
119 	if (ubamem(numuba, ECMEM, 32*2, 1) == 0) {
120 		printf("ecprobe: cannot reserve uba addresses\n");
121 		goto bad2;
122 	}
123 
124 	/*
125 	 * Make a one byte packet in what should be buffer #0.
126 	 * Submit it for sending.  This whould cause an xmit interrupt.
127 	 * The xmit interrupt vector is 8 bytes after the receive vector,
128 	 * so adjust for this before returning.
129 	 */
130 	*(u_short *)ecbuf = (u_short) 03777;
131 	ecbuf[03777] = '\0';
132 	addr->ec_xcr = EC_XINTEN|EC_XWBN;
133 	DELAY(100000);
134 	addr->ec_xcr = EC_XCLR;
135 	if (cvec > 0 && cvec != 0x200) {
136 		if (cvec & 04) {	/* collision interrupt */
137 			cvec -= 04;
138 			br += 1;		/* rcv is collision + 1 */
139 		} else {		/* xmit interrupt */
140 			cvec -= 010;
141 			br += 2;		/* rcv is xmit + 2 */
142 		}
143 	}
144 	return (1);
145 }
146 
147 /*
148  * Interface exists: make available by filling in network interface
149  * record.  System will initialize the interface when it is ready
150  * to accept packets.
151  */
152 ecattach(ui)
153 	struct uba_device *ui;
154 {
155 	struct ec_softc *es = &ec_softc[ui->ui_unit];
156 	register struct ifnet *ifp = &es->es_if;
157 	register struct ecdevice *addr = (struct ecdevice *)ui->ui_addr;
158 	struct sockaddr_in *sin;
159 	int i, j;
160 	u_char *cp;
161 
162 	ifp->if_unit = ui->ui_unit;
163 	ifp->if_name = "ec";
164 	ifp->if_mtu = ETHERMTU;
165 
166 	/*
167 	 * Read the ethernet address off the board, one nibble at a time.
168 	 */
169 	addr->ec_xcr = EC_UECLR;
170 	addr->ec_rcr = EC_AROM;
171 	cp = es->es_addr;
172 #define	NEXTBIT	addr->ec_rcr = EC_AROM|EC_ASTEP; addr->ec_rcr = EC_AROM
173 	for (i=0; i<6; i++) {
174 		*cp = 0;
175 		for (j=0; j<=4; j+=4) {
176 			*cp |= ((addr->ec_rcr >> 8) & 0xf) << j;
177 			NEXTBIT; NEXTBIT; NEXTBIT; NEXTBIT;
178 		}
179 		cp++;
180 	}
181 	sin = (struct sockaddr_in *)&es->es_if.if_addr;
182 	sin->sin_family = AF_INET;
183 	sin->sin_addr = arpmyaddr((struct arpcom *)0);
184 	ifp->if_init = ecinit;
185 	ifp->if_ioctl = ecioctl;
186 	ifp->if_output = ecoutput;
187 	ifp->if_reset = ecreset;
188 	for (i=0; i<16; i++)
189 		es->es_buf[i] = (u_char *)&umem[ui->ui_ubanum][ECMEM+2048*i];
190 	if_attach(ifp);
191 }
192 
193 /*
194  * Reset of interface after UNIBUS reset.
195  * If interface is on specified uba, reset its state.
196  */
197 ecreset(unit, uban)
198 	int unit, uban;
199 {
200 	register struct uba_device *ui;
201 
202 	if (unit >= NEC || (ui = ecinfo[unit]) == 0 || ui->ui_alive == 0 ||
203 	    ui->ui_ubanum != uban)
204 		return;
205 	printf(" ec%d", unit);
206 	(void) ubamem(uban, ECMEM, 32*2, 0);	/* mr disable (no alloc) */
207 	ecinit(unit);
208 }
209 
210 /*
211  * Initialization of interface; clear recorded pending
212  * operations, and reinitialize UNIBUS usage.
213  */
214 ecinit(unit)
215 	int unit;
216 {
217 	struct ec_softc *es = &ec_softc[unit];
218 	struct ecdevice *addr;
219 	register struct ifnet *ifp = &es->es_if;
220 	register struct sockaddr_in *sin;
221 	int i, s;
222 
223 	sin = (struct sockaddr_in *)&ifp->if_addr;
224 	if (sin->sin_addr.s_addr == 0)		/* address still unknown */
225 		return;
226 
227 	/*
228 	 * Hang receive buffers and start any pending writes.
229 	 * Writing into the rcr also makes sure the memory
230 	 * is turned on.
231 	 */
232 	if ((es->es_if.if_flags & IFF_RUNNING) == 0) {
233 		addr = (struct ecdevice *)ecinfo[unit]->ui_addr;
234 		s = splimp();
235 		for (i = ECRHBF; i >= ECRLBF; i--)
236 			addr->ec_rcr = EC_READ | i;
237 		es->es_oactive = 0;
238 		es->es_mask = ~0;
239 		es->es_if.if_flags |= IFF_UP|IFF_RUNNING;
240 		if (es->es_if.if_snd.ifq_head)
241 			ecstart(unit);
242 		splx(s);
243 	}
244 	if_rtinit(&es->es_if, RTF_UP);
245 	arpattach(&es->es_ac);
246 	arpwhohas(&es->es_ac, &sin->sin_addr);
247 }
248 
249 /*
250  * Start or restart output on interface.
251  * If interface is already active, then this is a retransmit
252  * after a collision, and just restuff registers.
253  * If interface is not already active, get another datagram
254  * to send off of the interface queue, and map it to the interface
255  * before starting the output.
256  */
257 ecstart(dev)
258 	dev_t dev;
259 {
260         int unit = ECUNIT(dev);
261 	struct ec_softc *es = &ec_softc[unit];
262 	struct ecdevice *addr;
263 	struct mbuf *m;
264 
265 	if (es->es_oactive)
266 		goto restart;
267 
268 	IF_DEQUEUE(&es->es_if.if_snd, m);
269 	if (m == 0) {
270 		es->es_oactive = 0;
271 		return;
272 	}
273 	ecput(es->es_buf[ECTBF], m);
274 
275 restart:
276 	addr = (struct ecdevice *)ecinfo[unit]->ui_addr;
277 	addr->ec_xcr = EC_WRITE|ECTBF;
278 	es->es_oactive = 1;
279 }
280 
281 /*
282  * Ethernet interface transmitter interrupt.
283  * Start another output if more data to send.
284  */
285 ecxint(unit)
286 	int unit;
287 {
288 	register struct ec_softc *es = &ec_softc[unit];
289 	register struct ecdevice *addr =
290 		(struct ecdevice *)ecinfo[unit]->ui_addr;
291 
292 	if (es->es_oactive == 0)
293 		return;
294 	if ((addr->ec_xcr&EC_XDONE) == 0 || (addr->ec_xcr&EC_XBN) != ECTBF) {
295 		printf("ec%d: stray xmit interrupt, xcr=%b\n", unit,
296 			addr->ec_xcr, EC_XBITS);
297 		es->es_oactive = 0;
298 		addr->ec_xcr = EC_XCLR;
299 		return;
300 	}
301 	es->es_if.if_opackets++;
302 	es->es_oactive = 0;
303 	es->es_mask = ~0;
304 	addr->ec_xcr = EC_XCLR;
305 	if (es->es_if.if_snd.ifq_head)
306 		ecstart(unit);
307 }
308 
309 /*
310  * Collision on ethernet interface.  Do exponential
311  * backoff, and retransmit.  If have backed off all
312  * the way print warning diagnostic, and drop packet.
313  */
314 eccollide(unit)
315 	int unit;
316 {
317 	struct ec_softc *es = &ec_softc[unit];
318 
319 	es->es_if.if_collisions++;
320 	if (es->es_oactive)
321 		ecdocoll(unit);
322 }
323 
324 ecdocoll(unit)
325 	int unit;
326 {
327 	register struct ec_softc *es = &ec_softc[unit];
328 	register struct ecdevice *addr =
329 	    (struct ecdevice *)ecinfo[unit]->ui_addr;
330 	register i;
331 	int delay;
332 
333 	/*
334 	 * Es_mask is a 16 bit number with n low zero bits, with
335 	 * n the number of backoffs.  When es_mask is 0 we have
336 	 * backed off 16 times, and give up.
337 	 */
338 	if (es->es_mask == 0) {
339 		es->es_if.if_oerrors++;
340 		printf("ec%d: send error\n", unit);
341 		/*
342 		 * Reset interface, then requeue rcv buffers.
343 		 * Some incoming packets may be lost, but that
344 		 * can't be helped.
345 		 */
346 		addr->ec_xcr = EC_UECLR;
347 		for (i=ECRHBF; i>=ECRLBF; i--)
348 			addr->ec_rcr = EC_READ|i;
349 		/*
350 		 * Reset and transmit next packet (if any).
351 		 */
352 		es->es_oactive = 0;
353 		es->es_mask = ~0;
354 		if (es->es_if.if_snd.ifq_head)
355 			ecstart(unit);
356 		return;
357 	}
358 	/*
359 	 * Do exponential backoff.  Compute delay based on low bits
360 	 * of the interval timer.  Then delay for that number of
361 	 * slot times.  A slot time is 51.2 microseconds (rounded to 51).
362 	 * This does not take into account the time already used to
363 	 * process the interrupt.
364 	 */
365 	es->es_mask <<= 1;
366 	delay = mfpr(ICR) &~ es->es_mask;
367 	DELAY(delay * 51);
368 	/*
369 	 * Clear the controller's collision flag, thus enabling retransmit.
370 	 */
371 	addr->ec_xcr = EC_CLEAR;
372 }
373 
374 /*
375  * Ethernet interface receiver interrupt.
376  * If input error just drop packet.
377  * Otherwise purge input buffered data path and examine
378  * packet to determine type.  If can't determine length
379  * from type, then have to drop packet.  Othewise decapsulate
380  * packet based on type and pass to type specific higher-level
381  * input routine.
382  */
383 ecrint(unit)
384 	int unit;
385 {
386 	struct ecdevice *addr = (struct ecdevice *)ecinfo[unit]->ui_addr;
387 
388 	while (addr->ec_rcr & EC_RDONE)
389 		ecread(unit);
390 }
391 
392 ecread(unit)
393 	int unit;
394 {
395 	register struct ec_softc *es = &ec_softc[unit];
396 	struct ecdevice *addr = (struct ecdevice *)ecinfo[unit]->ui_addr;
397 	register struct ether_header *ec;
398     	struct mbuf *m;
399 	int len, off, resid, ecoff, rbuf;
400 	register struct ifqueue *inq;
401 	u_char *ecbuf;
402 
403 	es->es_if.if_ipackets++;
404 	rbuf = addr->ec_rcr & EC_RBN;
405 	if (rbuf < ECRLBF || rbuf > ECRHBF)
406 		panic("ecrint");
407 	ecbuf = es->es_buf[rbuf];
408 	ecoff = *(short *)ecbuf;
409 	if (ecoff <= ECRDOFF || ecoff > 2046) {
410 		es->es_if.if_ierrors++;
411 #ifdef notdef
412 		if (es->es_if.if_ierrors % 100 == 0)
413 			printf("ec%d: += 100 input errors\n", unit);
414 #endif
415 		goto setup;
416 	}
417 
418 	/*
419 	 * Get input data length.
420 	 * Get pointer to ethernet header (in input buffer).
421 	 * Deal with trailer protocol: if type is PUP trailer
422 	 * get true type from first 16-bit word past data.
423 	 * Remember that type was trailer by setting off.
424 	 */
425 	len = ecoff - ECRDOFF - sizeof (struct ether_header);
426 	ec = (struct ether_header *)(ecbuf + ECRDOFF);
427 	ec->ether_type = ntohs((u_short)ec->ether_type);
428 #define	ecdataaddr(ec, off, type)	((type)(((caddr_t)((ec)+1)+(off))))
429 	if (ec->ether_type >= ETHERPUP_TRAIL &&
430 	    ec->ether_type < ETHERPUP_TRAIL+ETHERPUP_NTRAILER) {
431 		off = (ec->ether_type - ETHERPUP_TRAIL) * 512;
432 		if (off >= ETHERMTU)
433 			goto setup;		/* sanity */
434 		ec->ether_type = ntohs(*ecdataaddr(ec, off, u_short *));
435 		resid = ntohs(*(ecdataaddr(ec, off+2, u_short *)));
436 		if (off + resid > len)
437 			goto setup;		/* sanity */
438 		len = off + resid;
439 	} else
440 		off = 0;
441 	if (len == 0)
442 		goto setup;
443 
444 	/*
445 	 * Pull packet off interface.  Off is nonzero if packet
446 	 * has trailing header; ecget will then force this header
447 	 * information to be at the front, but we still have to drop
448 	 * the type and length which are at the front of any trailer data.
449 	 */
450 	m = ecget(ecbuf, len, off);
451 	if (m == 0)
452 		goto setup;
453 	if (off) {
454 		m->m_off += 2 * sizeof (u_short);
455 		m->m_len -= 2 * sizeof (u_short);
456 	}
457 	switch (ec->ether_type) {
458 
459 #ifdef INET
460 	case ETHERPUP_IPTYPE:
461 		schednetisr(NETISR_IP);
462 		inq = &ipintrq;
463 		break;
464 
465 	case ETHERPUP_ARPTYPE:
466 		arpinput(&es->es_ac, m);
467 		goto setup;
468 #endif
469 	default:
470 		m_freem(m);
471 		goto setup;
472 	}
473 
474 	if (IF_QFULL(inq)) {
475 		IF_DROP(inq);
476 		m_freem(m);
477 		goto setup;
478 	}
479 	IF_ENQUEUE(inq, m);
480 
481 setup:
482 	/*
483 	 * Reset for next packet.
484 	 */
485 	addr->ec_rcr = EC_READ|EC_RCLR|rbuf;
486 }
487 
488 /*
489  * Ethernet output routine.
490  * Encapsulate a packet of type family for the local net.
491  * Use trailer local net encapsulation if enough data in first
492  * packet leaves a multiple of 512 bytes of data in remainder.
493  * If destination is this address or broadcast, send packet to
494  * loop device to kludge around the fact that 3com interfaces can't
495  * talk to themselves.
496  */
497 ecoutput(ifp, m0, dst)
498 	struct ifnet *ifp;
499 	struct mbuf *m0;
500 	struct sockaddr *dst;
501 {
502 	int type, s, error;
503 	u_char edst[6];
504 	struct in_addr idst;
505 	register struct ec_softc *es = &ec_softc[ifp->if_unit];
506 	register struct mbuf *m = m0;
507 	register struct ether_header *ec;
508 	register int off;
509 	struct mbuf *mcopy = (struct mbuf *)0;
510 
511 	switch (dst->sa_family) {
512 
513 #ifdef INET
514 	case AF_INET:
515 		idst = ((struct sockaddr_in *)dst)->sin_addr;
516 		if (!arpresolve(&es->es_ac, m, &idst, edst))
517 			return (0);	/* if not yet resolved */
518 		if (in_lnaof(idst) == INADDR_ANY)
519 			mcopy = m_copy(m, 0, (int)M_COPYALL);
520 		off = ntohs((u_short)mtod(m, struct ip *)->ip_len) - m->m_len;
521 		/* need per host negotiation */
522 		if ((ifp->if_flags & IFF_NOTRAILERS) == 0)
523 		if (off > 0 && (off & 0x1ff) == 0 &&
524 		    m->m_off >= MMINOFF + 2 * sizeof (u_short)) {
525 			type = ETHERPUP_TRAIL + (off>>9);
526 			m->m_off -= 2 * sizeof (u_short);
527 			m->m_len += 2 * sizeof (u_short);
528 			*mtod(m, u_short *) = ntohs((u_short)ETHERPUP_IPTYPE);
529 			*(mtod(m, u_short *) + 1) = ntohs((u_short)m->m_len);
530 			goto gottrailertype;
531 		}
532 		type = ETHERPUP_IPTYPE;
533 		off = 0;
534 		goto gottype;
535 #endif
536 
537 	case AF_UNSPEC:
538 		ec = (struct ether_header *)dst->sa_data;
539 		bcopy((caddr_t)ec->ether_dhost, (caddr_t)edst, sizeof (edst));
540 		type = ec->ether_type;
541 		goto gottype;
542 
543 	default:
544 		printf("ec%d: can't handle af%d\n", ifp->if_unit,
545 			dst->sa_family);
546 		error = EAFNOSUPPORT;
547 		goto bad;
548 	}
549 
550 gottrailertype:
551 	/*
552 	 * Packet to be sent as trailer: move first packet
553 	 * (control information) to end of chain.
554 	 */
555 	while (m->m_next)
556 		m = m->m_next;
557 	m->m_next = m0;
558 	m = m0->m_next;
559 	m0->m_next = 0;
560 	m0 = m;
561 
562 gottype:
563 	/*
564 	 * Add local net header.  If no space in first mbuf,
565 	 * allocate another.
566 	 */
567 	if (m->m_off > MMAXOFF ||
568 	    MMINOFF + sizeof (struct ether_header) > m->m_off) {
569 		m = m_get(M_DONTWAIT, MT_HEADER);
570 		if (m == 0) {
571 			error = ENOBUFS;
572 			goto bad;
573 		}
574 		m->m_next = m0;
575 		m->m_off = MMINOFF;
576 		m->m_len = sizeof (struct ether_header);
577 	} else {
578 		m->m_off -= sizeof (struct ether_header);
579 		m->m_len += sizeof (struct ether_header);
580 	}
581 	ec = mtod(m, struct ether_header *);
582 	bcopy((caddr_t)edst, (caddr_t)ec->ether_dhost, sizeof (edst));
583 	ec->ether_type = htons((u_short)type);
584 	bcopy((caddr_t)es->es_addr, (caddr_t)ec->ether_shost, 6);
585 
586 	/*
587 	 * Queue message on interface, and start output if interface
588 	 * not yet active.
589 	 */
590 	s = splimp();
591 	if (IF_QFULL(&ifp->if_snd)) {
592 		IF_DROP(&ifp->if_snd);
593 		error = ENOBUFS;
594 		goto qfull;
595 	}
596 	IF_ENQUEUE(&ifp->if_snd, m);
597 	if (es->es_oactive == 0)
598 		ecstart(ifp->if_unit);
599 	splx(s);
600 	return (mcopy ? looutput(&loif, mcopy, dst) : 0);
601 
602 qfull:
603 	m0 = m;
604 	splx(s);
605 bad:
606 	m_freem(m0);
607 	return (error);
608 }
609 
610 /*
611  * Routine to copy from mbuf chain to transmit
612  * buffer in UNIBUS memory.
613  * If packet size is less than the minimum legal size,
614  * the buffer is expanded.  We probably should zero out the extra
615  * bytes for security, but that would slow things down.
616  */
617 ecput(ecbuf, m)
618 	u_char *ecbuf;
619 	struct mbuf *m;
620 {
621 	register struct mbuf *mp;
622 	register int off;
623 	u_char *bp;
624 
625 	for (off = 2048, mp = m; mp; mp = mp->m_next)
626 		off -= mp->m_len;
627 	if (2048 - off < ETHERMIN + sizeof (struct ether_header))
628 		off = 2048 - ETHERMIN - sizeof (struct ether_header);
629 	*(u_short *)ecbuf = off;
630 	bp = (u_char *)(ecbuf + off);
631 	for (mp = m; mp; mp = mp->m_next) {
632 		register unsigned len = mp->m_len;
633 		u_char *mcp;
634 
635 		if (len == 0)
636 			continue;
637 		mcp = mtod(mp, u_char *);
638 		if ((unsigned)bp & 01) {
639 			*bp++ = *mcp++;
640 			len--;
641 		}
642 		if (off = (len >> 1)) {
643 			register u_short *to, *from;
644 
645 			to = (u_short *)bp;
646 			from = (u_short *)mcp;
647 			do
648 				*to++ = *from++;
649 			while (--off > 0);
650 			bp = (u_char *)to,
651 			mcp = (u_char *)from;
652 		}
653 		if (len & 01)
654 			*bp++ = *mcp++;
655 	}
656 	m_freem(m);
657 }
658 
659 /*
660  * Routine to copy from UNIBUS memory into mbufs.
661  * Similar in spirit to if_rubaget.
662  *
663  * Warning: This makes the fairly safe assumption that
664  * mbufs have even lengths.
665  */
666 struct mbuf *
667 ecget(ecbuf, totlen, off0)
668 	u_char *ecbuf;
669 	int totlen, off0;
670 {
671 	register struct mbuf *m;
672 	struct mbuf *top = 0, **mp = &top;
673 	register int off = off0, len;
674 	u_char *cp;
675 
676 	cp = ecbuf + ECRDOFF + sizeof (struct ether_header);
677 	while (totlen > 0) {
678 		register int words;
679 		u_char *mcp;
680 
681 		MGET(m, M_DONTWAIT, MT_DATA);
682 		if (m == 0)
683 			goto bad;
684 		if (off) {
685 			len = totlen - off;
686 			cp = ecbuf + ECRDOFF +
687 				sizeof (struct ether_header) + off;
688 		} else
689 			len = totlen;
690 		if (len >= CLBYTES) {
691 			struct mbuf *p;
692 
693 			MCLGET(p, 1);
694 			if (p != 0) {
695 				m->m_len = len = CLBYTES;
696 				m->m_off = (int)p - (int)m;
697 			} else {
698 				m->m_len = len = MIN(MLEN, len);
699 				m->m_off = MMINOFF;
700 			}
701 		} else {
702 			m->m_len = len = MIN(MLEN, len);
703 			m->m_off = MMINOFF;
704 		}
705 		mcp = mtod(m, u_char *);
706 		if (words = (len >> 1)) {
707 			register u_short *to, *from;
708 
709 			to = (u_short *)mcp;
710 			from = (u_short *)cp;
711 			do
712 				*to++ = *from++;
713 			while (--words > 0);
714 			mcp = (u_char *)to;
715 			cp = (u_char *)from;
716 		}
717 		if (len & 01)
718 			*mcp++ = *cp++;
719 		*mp = m;
720 		mp = &m->m_next;
721 		if (off == 0) {
722 			totlen -= len;
723 			continue;
724 		}
725 		off += len;
726 		if (off == totlen) {
727 			cp = ecbuf + ECRDOFF + sizeof (struct ether_header);
728 			off = 0;
729 			totlen = off0;
730 		}
731 	}
732 	return (top);
733 bad:
734 	m_freem(top);
735 	return (0);
736 }
737 
738 /*
739  * Process an ioctl request.
740  */
741 ecioctl(ifp, cmd, data)
742 	register struct ifnet *ifp;
743 	int cmd;
744 	caddr_t data;
745 {
746 	register struct ifreq *ifr = (struct ifreq *)data;
747 	int s = splimp(), error = 0;
748 
749 	switch (cmd) {
750 
751 	case SIOCSIFADDR:
752 		if (ifp->if_flags & IFF_RUNNING)
753 			if_rtinit(ifp, -1);	/* delete previous route */
754 		ecsetaddr(ifp, (struct sockaddr_in *)&ifr->ifr_addr);
755 		ecinit(ifp->if_unit);
756 		break;
757 
758 	default:
759 		error = EINVAL;
760 	}
761 	splx(s);
762 	return (error);
763 }
764 
765 ecsetaddr(ifp, sin)
766 	register struct ifnet *ifp;
767 	register struct sockaddr_in *sin;
768 {
769 
770 	ifp->if_addr = *(struct sockaddr *)sin;
771 	ifp->if_net = in_netof(sin->sin_addr);
772 	ifp->if_host[0] = in_lnaof(sin->sin_addr);
773 	sin = (struct sockaddr_in *)&ifp->if_broadaddr;
774 	sin->sin_family = AF_INET;
775 	sin->sin_addr = if_makeaddr(ifp->if_net, INADDR_ANY);
776 	ifp->if_flags |= IFF_BROADCAST;
777 }
778